RVO reported that sporadic small ash emissions from Manam?s Southern Crater were observed starting at the end of September.
Nighttime incandescence began on 8 October and incandescent material was occasionally ejected from the crater.
The activity was characterized as moderately Strombolian with incandescent material rolling down SW Valley, visibly appearing as short lava flows.
The Darwin VAAC noted that on 18 October an ash plume rose to 2.4 km (8,000 ft) a.s.l.
and drifted NW.
A thermal anomaly was visible in satellite images.
RVO stated that at around 0800 on 20 October a large explosion at Southern Crater produced ash plumes that rose at least 1 km above the summit and drifted N and NW.
According to the Darwin VAAC ash plumes rose as high as 15.2 km (50,000 ft) a.s.l.
between 0840-0950, expanded radially, and then drifted E.
Lower-level plumes rose 4.6-5.5 km (15,000-18,000 ft) a.s.l.
and drifted NW.
Later that day a collapse of newly erupted material, as well deposits from the previous few weeks, produced a debris flow that originated at the head of the valley and descended the SW Valley.
Sources: Darwin Volcanic Ash Advisory Centre (VAAC),Rabaul Volcano Observatory (RVO)
Asosan (Japan)
